Japanese Patent Application Laid-Open Nos. 2010-21001 and 2008-186786 discloses that some vehicle lights such as vehicle headlamps are conventionally known which allow a beam of light incident upon an end face of a light guide plate (or a lens) to be transmitted from the front end face of the light guide plate.
The vehicle lights disclosed in these patent references employ a light guide plate having a reflective structure such as reflective dots on the rear end face, so that the light incident upon the lower face of the light guide plate can be reflected by the reflective structure provided on the rear end face and then transmitted from the front end face, thereby allowing the front end face of the light guide plate to emit light.
However, the vehicle lights disclosed in the above patent references can control the light incident on the lower face of the light guide plate not in the right-to-left direction but only in the back-and-forth direction. Thus, in the conventional art, it may not always be possible for one light source to emit light from an area widened in the right-to-left direction on the front end face of the light guide plate. Accordingly, in the conventional art, to emit light from a widened area on the front end face of the light guide plate elongated in the right-to-left direction, a number of light sources have to be disposed in the right-to-left direction, which may lead to additional parts costs.
Furthermore, the vehicle lights disclosed in the above patent references only allow the light reflected by the reflective structure provided on the rear end face of the light guide plate to be transmitted from the front end face of the light guide plate. This may cause variations in brightness depending on the distance from the light source in a manner such that a portion on the front end face closer to the light source can emit light at a greater intensity. It may not, therefore, be possible to provide uniform emission through the front end face of the light guide plate. In particular, the reflective structure with a plurality of reflective dots formed on the rear end face of the light guide plate would cause the vicinity of the reflective dots to transmit light through the front end face of the light guide plate at a greater intensity when compared with the other portions. Thus, this would also cause variations in brightness depending on the distance from the reflective dots in addition to variations in brightness depending on the distance from the light source.